Liebermann reagent

The Liebermann reagent named after Hungarian chemist Leo Liebermann (1852-1926) is used as a simple spot-test to presumptively identify alkaloids as well as other compounds. It is composed of a mixture of potassium nitrite and concentrated sulfuric acid.^[1][2] 1 g of potassium nitrite is used for every 10 mL of sulfuric acid.^[3] Potassium nitrite may also be substituted by sodium nitrite.^[4][5] It is used to test for cocaine, morphine, PMA and PMMA.

The test is performed by scraping off a small amount of the substance and adding a drop of the reagent (which is initially clear and colorless). The results are analyzed by viewing the color of the resulting mixture, and by the time taken for the change in color to become apparent.

Final colors produced by Liebermann Reagent with various substances

Substance	Color
Alprazolam	No reaction
Cocaine	Yellowish[2]
Morphine	Black[2][6]
Atropine	Red - orange[citation needed]
Yohimbine	Blue[citation needed]
PMA and PMMA	Purple - brown[7]
MDMA	Intense brown[8] - black[7]
Amphetamine	Orange to red[9]
Methamphetamine	Red[6]
4-FA	Orange[10][11]
Cathinone	Bright yellow[8]
Methcathinone	Bright yellow[8]
4-MMC	Bright yellow[8]
N,N-DMC	Faint yellow[8]
3-FMC	No reaction[8]
4-MOMC	Faint orange[8]
Methylone	Orange > brown[8]
MDPV	Yellow > green[8]
4-Me-PPP	Orange[12]
Brephedrone	Yellow[12]
4-MEC	Orange[12]
Pentedrone	Yellow[12]
4-Methylbuphedrone	Yellow[12]
Buphedrone	Yellow[12]
Butylone	Yellow > brown[12] or green > brown[8]
3,4-DMMC	Orange[12]
Naphyrone	Brown[12]
Benzedrone	Orange[12]
JWH-307	Dark yellow[12]
AB-001	Dark yellow[12]
CB-13	Dark green[12]
JTE-907	Black (bubbling)[12]
UR-144	Dark red[12]
URB-597	Yellow brown[12]
URB602	Dark brown[12]
URB754	Light brown[12]
AM-1248	Dark yellow[12]
AB-034	Red-orange > dark red[12]
A-796,260	Red-orange > dark red[12]
A-834,735	Red-orange > dark red[12]
FUR-144	Dark red[12]
APINACA	No color change[12]
JWH-073	Yellow - brown[12]
JWH-018	Yellow - brown[12]
JWH-200	Dark yellow - brown[12]
AM-2201	Yellow - brown[12]
JWH-203	Yellow - orange[12]
RCS-4-C4 homolog	Brown[12]
AM-694	Dark yellow[12]
MAM-2201	Green - brown[12]
AM-2233	Yellow[12]
STS-135 (drug)	Brown[12]
4-MeO-PCP	Brown[12]
Methoxetamine	Orange - brown[12]
Ethketamine	Pale yellow[12]
3-HO-PCE	Dark brown[12]
5-MeO-DALT	Dark brown - black[12]
4-methyl-aET	Brown[12]
4-AcO-DALT	Black[12]
4-HO-MET	Black[12]
4-HO-MIPT	Black[12]
4-AcO-DET	Black[12]
DPT	Dark brown
aMT	Black[12]
5-IT	Dark brown[12]
5-APB	Black[12]
6-APB	Dark purple[12]
Camfetamine	Dark red[12]
Methiopropamine	Dark brown[12]
MDAI	Green > black[12]
5-IAI	Dark brown[12]
Pethidine	Red - orange[13]
Mescaline	Black[13]
Allylescaline	Brown - black[12]
2C-T-2	Red[12]
2C-P	Green[12]
2C-C	Yellow > black > clear
2C-B	Yellow → black
b-methoxy-2C-D	Green[12]

See also

• Drug checking
• Liebermann–Burchard test
• Dille–Koppanyi reagent
• Folin's reagent
• Froehde reagent
• Mandelin reagent
• Marquis reagent
• Mecke reagent
• Simon's reagent
• Zwikker reagent